As the internet has grown, malware has become a major concern for businesses and individuals connected to the internet and other networks. Malware (i.e., worms, spyware, etc.) may target particular vulnerabilities of applications that may be running on a server. For example, server applications are widely available to respond to messages from any requesting party (e.g., a web server configured to respond to HTTP requests) and network messages may be crafted with payloads intentionally designed to exploit a vulnerability of a server. For example, a network message may include a payload that causes a buffer overflow on a vulnerable system, allowing a remote attacker to execute arbitrary shell code on a host system.
Because of the large number and variety of malware attacks that occur today, security systems, known as intrusion prevention systems (IPS) have been developed to automatically block malicious traffic using a database of malicious payload signatures. For example, a network administrator may deploy an IPS on a host system or at a gateway edge between a local network and the internet. When the IPS detects a malicious payload signature in a payload addressed to a server on that host, it may simply drop that message. That is, the IPS intercepts the message, preventing it from being forwarded towards a destination. Further, the IPS raises an alarm and even blocks future traffic from the source address.